Microstructure and mechanical properties of welded joints of \mathbfT i_\mathbf2 \mathbfA I N b and \mathbfT C 4 by laser oscillation scanning

Laser oscillation scanning welding technique was used to perform heterogeneous metal welding tests on 2 mm thick Ti-22Al-25 Nb alloy and TC4 alloy. The microstructure evolution and mechanical properties of the laser oscillation scanning welded joints were studied. The results showed that the laser oscillation scanning welding technique can be used to obtain well formed welded joints without cracks, porosity and other defects. Microstructure of the weld was mainly composed of B2 phase and \alpha^\prime martensite phase. The average tensile strength of the joint could reach 88.6 \% of that of the TCA base material. When the laser scanning frequency reached 500 Hz, the grain was refined and the tensile strength and elongation after fracture of the weld were effectively improved.